While just one in 20 people nationwide used public transit to commute to work in 2012, nearly one in five in Seattle did so, more than in most cities. Last year, contractors began building a 1.7 mile tunnel in Seattle last year to replace the damaged SR 99 highway running through the city. The $1.44 billion project is intended to expand public space along the city’s waterfront. Seattle is also one of a few cities that uses streetcars, and was one of the nation’s top cities for public transit, according to Walk Score. One in five workers used public transportation to get to work in 2012, higher than most U.S. cities.

While nearly 20% of households in Milwaukee did not have a car as of 2012, many residents still depend on vehicles. That year, 10.8% of residents carpooled to work, higher than the 8.6% who got to work using public transportation. For Milwaukee residents who do elect to use public transportation, the Milwaukee County Transit System provides regular bus service. According to its website, more than 85% of county residents live within walking distance of a bus route. The system also provides a “freeway flyer” bus service that provides transportation from the city’s suburbs to downtown Milwaukee.

Just 21.2% of Detroit households did not have a vehicle in 2007. By 2012, that figure jumped to more than 26%. Residents’ especially low incomes may be one reason for the high percentage of households without a car; the city’s median household income was just $23,600, or well less than half the U.S. median of over $51,000. Detroit had, by far, the lowest walk score of any city where so few households had a car. According to a 2011 analysis by the Brookings Institution, just 59.7% of working-age residents in the Detroit metro area were served by transit systems, lower than more than half of the metro areas reviewed. One public transportation system, the Detroit People Mover, is little-used and extremely expensive to maintain.

Overall, more than 40% of Chicago residents did not use their own vehicle to commute in 2012, more than in most U.S. cities. To get to work, more than one in four residents used public transportation, more than in all but a few cities. Many others chose to walk to work — city residents were more likely to walk than Americans nationwide. According to Mayor Rahm Emanuel, public transportation is essential to the economic development of the city. In a speech last year, the mayor cited numerous renovations and projects aimed at strengthening the public transportation infrastructure.

The percentage of Baltimore households without a car rose from 29.3% in 2007 to 31.2% in 2012. One reason may be the quality of walking routes and public transportation in the city; Baltimore received some of the top marks in the nation for both walking and public transportation. The Maryland Transit Administration operates a number of services, including commuter buses and trains, as well as a more-than 15 mile-long subway. In 2012, more than 19% of commuters took public transportation to work, one of the higher percentages in the nation. There are also plans to build a new light-rail system, called the Red Line.